Hillary Clinton’s chief argument walking into Iowa is that Bernie Sanders cannot beat a Republican in the general election. The polls say she’s wrong.

According to survey after survey, Sanders runs equal to or better than Clinton in general-election matchups with the top Republican presidential candidates.

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“Not only is Bernie Sanders electable in the general election,” insisted Sanders senior adviser Tad Devine, “he’s a stronger candidate than Hillary Clinton in the general election.”

Indeed, public pollsters who’ve conducted surveys in both Iowa and New Hampshire caution that the Sanders team might be misreading the data the campaign is relying on to make its case that Sanders would broaden the Democratic electorate and make more states competitive by luring young, more independently minded voters.

Patrick Murray, who runs the Monmouth University Polling Institute in New Jersey, said the independent voters who are backing Sanders in the primary are more liberal in orientation and would be likely to vote for the Democrat in November anyway.

“It’s a big leap of faith to take primary poll data and jump to the general,” added Lee Miringoff, the director of the Marist College Institute for Public Opinion, which has conducted recent polls for NBC News and The Wall Street Journal. “You do ask the questions, and it tells you something: Hillary has a problem with independents, and Bernie doesn’t. Fast forward to September, October and November. The campaigns will change, and that dynamic will be different.”

The increasing competitiveness of the presidential race has left many Democrats to consider how a Sanders nomination would affect their party’s chances at keeping the White House, and it’s become a frequent talking point on the campaign trail as Clinton and Sanders’ make their final pitches to voters in both early states.

The Clinton campaign insists the former secretary of state is the strongest potential candidate in the fall, and Clinton allies are warning that picking Sanders would jeopardize not only Democrats’ hold on the presidency, but also damage the party’s prospects to win back the Senate and make inroads on Republicans’ wide House majority.

National polls of general-election matchups are unreliable measures at this stage of the campaign, and they render an inconclusive verdict on which Democrat is more electable. Estimations by the website HuffPollster show both candidates running similarly against the three top GOP candidates: Donald Trump, Ted Cruz and Marco Rubio.

The Clinton campaign, along with much of the Democratic establishment, believes those numbers would change in a general election. Republicans would attack Sanders as a tax-raising socialist they say.

“Socialist” could be a one-word silver bullet against Sanders: A Pew Research Center poll in late 2011 found a majority of Americans, 60 percent, had an unfavorable opinion of socialism, compared to 31 percent who had a favorable opinion.

“It’s very clear who Republicans want to run against in November,” said Justin Barasky, communications director for the pro-Clinton super PAC Priorities USA. “That’s why they have spent roughly $6 million against Hillary Clinton. That’s why there’s a Republican super PAC pretending to go negative against Bernie Sanders.”

(The Clinton campaign did not respond to requests to comment on this story.)

Sanders’ team counters by pointing to Iowa and New Hampshire – two states they say know the Vermont senator best. A WMUR-TV/CNN poll last week showed Sanders running considerably ahead of Clinton when matched up with the Republican candidates.

“These are the two states where voters have received the most information about the candidates,” said Devine.

Devine insists Sanders would scramble the traditional Electoral College map. The battleground states – states in which the campaign is legitimately contested – remain largely unchanged since George W. Bush eked out a 4-vote victory in 2000.

Citing his candidate’s appeal to younger voters, independents and those otherwise disillusioned with politics, Devine said Sanders could put in play a number of states that have been reliably Republican for decades.

He mentioned specifically a number of states in the Deep South with high African-American populations but that have still backed Republicans by wide margins.

“We’d have to take a real hard look at a state like Georgia, for example,” Devine said. “A state like Louisiana, where Democrats haven’t competed since Bill Clinton won it in 1996, we’re going to have to take a look at that.”

(President Barack Obama didn’t campaign in either state, despite wide popularity with black voters – and lost Georgia and Louisiana by 7 and 17 points, respectively.)

He didn’t stop there, mentioning Alabama, which Mitt Romney won by 23 points, and Mississippi, which has the greatest black share of the population of any state (excepting the District of Columbia) but still gave Romney an easy, 11-point victory four years ago.

Outside the South, Devine pointed to Montana, which Obama nearly won in 2008 but lost by a double-digit margin four years later) and Arizona, where demographic change is making the state more competitive, but Republicans still dominate.

“I think a lot of states which haven’t been part of the overall [Democratic] targeting could come into play,” he said.

Devine said the Sanders campaign would also seek to help Democrats in competitive Senate, House and governor’s races – opening up the possibility of investing time and resources in states that are either solidly Democratic or Republican at the presidential level to boost down-ballot candidates.

But a number of Democrats in states with competitive races don’t agree. Take Missouri, which went to John McCain by the slimmest of margins in 2008 but was won easily by Romney in 2012. The two parties are locked in competitive races for Senate and governor, even if the presidential race there doesn’t end up being competitive.

Jay Nixon, the outgoing Democratic governor, told The New York Times that a Sanders nomination would be “a meltdown all the way down the ballot.” Sen. Claire McCaskill, a fellow Missouri Democrat, said Sanders would make it “impossible for Democrats in a state like Missouri.”

But while some Democrats are starting to wring their hands over Sanders’ surge, their downballot candidates are not yet preparing for the Vermonter’s nomination in the same way Republicans are girding for the possibility that Donald Trump or Ted Cruz would be at the top of the ticket – scenarios that could also impact the Electoral College map.

And, for their part, Republicans are keeping their ammunition focused on Clinton, not Sanders. Of the 19 tweets the Republican National Committee has highlighted this week in the morning newsletter the committee sends to reporters, all 19 have either been critical of Clinton’s policies or ethics – or trumpeted Sanders’ rise in the polls.